Dizzying sky over Mono Lake located on the eastern slope of the Sierra Nevada. If you're not sure what's happening in this photo - this is a result of letting my camera take photos continuously for 3 hours, capturing the apparent movement of the stars due to Earth's rotation. When facing north the stars appear to be circling around the North Star.

Mono Lake is one of the oldest and saltiest lakes in North America (it's 3 times saltier than the ocean!). But its most unusual features are the dramatic tufa towers emerging from the surface. These rock towers form when underwater springs rich in calcium mix with the waters of the lake, which are rich in carbonates. The resulting reaction forms limestone. Over time the buildup of limestone formed towers, and when the water level of the lake dropped the towers became exposed.